MKV to MP4 Converter
Turn Matroska MKV files from OBS, a capture card or a download into MP4 video that phones, smart TVs, editing apps and upload forms accept without a special player.
Video Converter
or drag MP4, MOV, MKV … files here ·
Up to 95 MB each· 20 files at once· Removed after 30 min
Your files are removed from our servers 30 minutes after processing.
Lower is better quality and a bigger file. 18 looks identical to the source, 23 is the default, 28 and above shows visible softening.
Frames per second. Keep the source rate unless a platform asks for a specific one; 15–20 fps is plenty for GIFs.
Only used for PowerPoint files and single still images: how long each slide or picture stays on screen.
Auto uses AAC for MP4/MOV and Opus for WebM. Copy keeps the original sound untouched when the new format supports it.
192 kbps is transparent for music; 128 kbps is enough for speech.
Width of the animation in pixels; height follows the aspect ratio. 480 px suits chats, 720 px or more gives a high-quality GIF but a much larger file.
GIF holds at most 256 colors. Fewer colors make a smaller file but cause banding on gradients and skin tones.
Mixes palette colors in a fine pattern to hide banding. Sierra gives the smoothest result; none gives the smallest file.
Whether the animation repeats endlessly or plays one time and stops.
Optional. Seconds (e.g. 75) or minutes:seconds (1:15). Leave empty to start at the beginning.
Optional. Same format as the start time. Leave empty to keep everything up to the end.
The converted file will be at or just under this size.
Files are deleted 30 minutes after processingPrivacy policy
2024
The year the IETF published Matroska, the container behind .mkv files, as RFC 9559.
Matroska had been in wide use for many years before it became an IETF standard. Read RFC 9559.
Why so many videos arrive as MKV
MKV is the file extension of Matroska, an open container that can hold almost any video codec, any number of audio tracks, subtitle tracks, chapters and attachments in one file. That flexibility is why it shows up in so many places: OBS Studio and other recording tools offer it, capture cards and some cameras write it, and videos with several languages or subtitle tracks are often distributed as MKV.
Recording software likes MKV for a practical reason. If the computer crashes or the power goes off in the middle of a recording, an MKV file stays readable up to the last moment, while an interrupted MP4 can lose everything because its index is only written at the end. Recording to MKV and converting to MP4 afterwards is therefore a common workflow, and many streamers follow it.
The downside appears when the file leaves the computer it was made on. Phones, TVs, video editors and websites differ a lot in how much of Matroska they support, while MP4 with H.264 video and AAC audio plays nearly everywhere.
Matroska MKV and MP4 compared
MKV
MKV video
Matroska, an open container first released in 2002. It can bundle several video, audio and subtitle tracks, plus chapters, in one file. Desktop players like VLC open it easily, while phones, editors and upload sites more often expect MP4.
- Lossy or lossless
- Open standard
MP4
MP4 video
The MPEG-4 Part 14 container, standardized in 2001 and now the default for online video. It usually carries H.264 or HEVC video with AAC audio, all lossy, plus optional subtitles. Phones, browsers, smart TVs and social platforms all play it.
- Lossy
- Open standard
Why convertThis direction trades Matroska's room for many tracks and subtitles for the one container that every phone, TV and editor accepts. Convert to MP4 when a single video with one soundtrack is what you need to share or edit.
Both are containers, so the real question is what sits inside. An MKV recorded by OBS usually holds H.264 video and AAC audio already, which MP4 can carry as they are. MKV files from other sources may hold codecs such as VP9 or HEVC, or audio in formats MP4 players do not expect, and those are converted on the way.
That is why the video codec is set to Auto on this page. Auto writes H.264 for maximum compatibility, while letting the converter keep quality as close to the source as possible. If you know the file has to play on an old phone or a basic TV, setting H.264 explicitly gives the same result and makes the choice visible.
How to convert MKV to MP4
Add the MKV files
Drop one or more .mkv files on the box above, or press Choose Files.
Leave the codec on Auto
MP4 with Auto video codec and AAC audio is preset. Pick H.264 under Advanced settings if the file must play on old devices.
Convert and download
Press Convert and save the MP4 files, ready to edit, upload or copy to a phone.
MKV to MP4 questions
Why does OBS record to MKV?
MKV keeps everything recorded up to the moment of a crash or power cut, while an interrupted MP4 recording can be unreadable. That makes MKV the safer recording format, and MP4 the better format for sharing afterwards.
Does an MKV lose quality when it becomes an MP4?
With the codec on Auto, the converter keeps the picture as close to the source as it can. When the MKV holds H.264 video, the MP4 is visually identical. Other codecs are encoded again at a quality that looks the same in normal viewing.
What happens to the subtitles inside my MKV?
Soft subtitle tracks are not carried into the MP4. Extract or convert them separately, or keep a copy of the MKV, so the subtitles are not lost.
My MKV has two audio languages. Which one do I get?
The main audio track, which is usually the first one listed in the file. If you need another language, convert from a copy of the file where that track is set as the default.
Why won't my TV play the MKV from a USB stick?
Many TVs read MKV but not every codec inside it, or not at every resolution. An MP4 with H.264 and AAC is the combination smart TVs play most reliably.
Can I convert a long gaming recording?
Files up to 95 MB per upload are accepted. Trim a long session to the part you need with Start at and End at, or cut it first with the Trim Video tool.
Tracks that do not make the trip
An MP4 made here holds one video track and one audio track. For screen recordings and camera files that is everything there is. For films and series with several languages, commentary tracks or subtitles, it means a choice has to be made, and the rest stays behind in the MKV.
Recordings from OBS can also contain more than one audio track when you record the microphone and the game or desktop sound separately. The main track is the one that ends up in the MP4, which usually holds the mixed sound. If you need the separate tracks for editing, keep the MKV and import it into an editor that reads Matroska.
Keep the MKV if it has extras
Converting keeps the picture and the main soundtrack only. Hold on to the original file when it contains:
- Subtitle tracks you want to keep
- Audio in more than one language
- Separate microphone and game audio tracks
- Chapters or attached fonts
Batch conversion and other options
- Remux
- Also called rewrap · container change
- Moving the existing video and audio streams into a different container without encoding them again. It is fast and lossless, but it only works when the target container supports the codecs already in the file.
Each batch accepts up to 20 MKV files, each up to 95 MB. Every file gets the same settings, and you download the MP4s one by one or together. Uploaded files are removed after processing and the converted ones 30 minutes later.
Many recording tools can also remux to MP4 themselves; OBS Studio, for example, has a remux option in its File menu. That works when the recording already uses MP4-friendly codecs. The converter here is the route when you are on another computer, when the codecs need changing, or when a batch of files from different sources has to come out the same way.
If you only need the sound, for example the commentary of a recording, Video to Audio extracts it straight to MP3 or WAV. For other target formats, such as MOV for Apple editing apps or WebM for a website, use the Video Converter page, and the Compress Video tool helps when the MP4 is too large to send.
| Other ways to get MP4 | |
|---|---|
| Other ways to get MOV | |
| Other ways to get WEBM | |
| Other 3GP conversions | |
| Other AVI conversions | |
| Related conversions |
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